php mcrypt CBC

<?php/** * 加密解密类   *  * @author zhenghua * @time   2015/4/29 */// include_once "errorCode.php";class App_encrypt{public static $block_size = 32;   //块大小public $key;/** * 对明文进行加密 * @param string $text 需要加密的明文 * @return string 加密后的密文 */public function encrypt($k, $text, $appid){$this->key = base64_decode($k . "=");//微信的拼装 base64try {//获得16位随机字符串，填充到明文之前$random = $this->getRandomStr();$text = $random . pack("N", strlen($text)) . $text . $appid;// 网络字节序$size = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);$module = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, '');$iv = substr($this->key, 0, 16);//使用自定义的填充方式对明文进行补位填充$text = $this->cover_position($text);mcrypt_generic_init($module, $this->key, $iv);//加密$encrypted = mcrypt_generic($module, $text);mcrypt_generic_deinit($module);mcrypt_module_close($module);return array(ErrorCode::$OK, urlencode(base64_encode($encrypted)));} catch (Exception $e) {return array(ErrorCode::$EncryptAESError, null);}}/** * 对密文进行解密 * @param string $encrypted 需要解密的密文 * @return string 解密得到的明文 */public function decrypt($k, $encrypted, $appid){$this->key = base64_decode($k . "=");//微信的拼装 base64try {$encrypted = urldecode($encrypted);$encrypted = str_replace(' ','+',$encrypted);//加号补全$ciphertext_dec = base64_decode($encrypted);$module = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, '');$iv = substr($this->key, 0, 16);mcrypt_generic_init($module, $this->key, $iv);//解密$decrypted = mdecrypt_generic($module, $ciphertext_dec);mcrypt_generic_deinit($module);mcrypt_module_close($module);} catch (Exception $e) {return array(ErrorCode::$DecryptAESError, null);}try {//去除补位字符$result = $this->remove_cover($decrypted);//去除16位随机字符串,网络字节序和AppIdif (strlen($result) < 16)throw new Exception("null") ;$content = substr($result, 16, strlen($result));$len_list = unpack("N", substr($content, 0, 4));$xml_len = $len_list[1];$xml_content = substr($content, 4, $xml_len);$from_appid = substr($content, $xml_len + 4);} catch (Exception $e) {return array(ErrorCode::$IllegalBuffer, null);}if ($from_appid != $appid)return array(ErrorCode::$ValidateAppidError, null);return array(0, $xml_content);}/** * 随机生成16位字符串 * @return string 生成的字符串 */function getRandomStr(){$str = "";$str_pol = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz";$max = strlen($str_pol) - 1;for ($i = 0; $i < 16; $i++) {$str .= $str_pol[mt_rand(0, $max)];}return $str;}/** * 对需要加密的明文进行填充补位 * @param $text 需要进行填充补位操作的明文 * @return 补齐明文字符串 */function cover_position($text){$block_size = App_encrypt::$block_size;$text_length = strlen($text);//计算需要填充的位数$amount_to_pad = App_encrypt::$block_size - ($text_length % App_encrypt::$block_size);if ($amount_to_pad == 0) {$amount_to_pad = App_encrypt::block_size;}//获得补位所用的字符$pad_chr = chr($amount_to_pad);$tmp = "";for ($index = 0; $index < $amount_to_pad; $index++) {$tmp .= $pad_chr;}return $text . $tmp;}/** * 对解密后的明文进行补位删除 * @param decrypted 解密后的明文 * @return 删除填充补位后的明文 */function remove_cover($text){$pad = ord(substr($text, -1));if ($pad < 1 || $pad > 32) {$pad = 0;}return substr($text, 0, (strlen($text) - $pad));}/** * 用SHA1算法生成安全签名 * @param array  string 加密数据 */public static function getSHA1($string){//排序try {$str = $string;return array(ErrorCode::$OK, sha1($str));} catch (Exception $e) {return array(ErrorCode::$ComputeSignatureError, null);}}}class ErrorCode{public static $OK = 0;public static $ValidateSignatureError = -40001;public static $ParseXmlError = -40002;public static $ComputeSignatureError = -40003;public static $IllegalAesKey = -40004;public static $ValidateAppidError = -40005;public static $EncryptAESError = -40006;public static $DecryptAESError = -40007;public static $IllegalBuffer = -40008;public static $EncodeBase64Error = -40009;public static $DecodeBase64Error = -40010;public static $GenReturnXmlError = -40011;}